Lined container



y 14, 8 A. L. M GEE 3,383,026

L I NED CONTAINER Original Filed June 17, 1965 I? 29 r I 35 UnitedStates Patent 0 3,383,026 LINED CONTAINER Arthur L. McGee, San Jose,Calif., assignor to FMC Corporation, Philadelphia, Pa., a corporation ofDelaware Original application June 17, 1965, Ser. No. 464,711, nowPatent No. 3,338,020, dated Aug. 29, 1967. Divided and this applicationApr. 18, 1967, Ser. No. 631,634

4 Claims. (Cl. 229-14) ABSTRACT OF THE DISCLOSURE A container having agenerally rigid supporting tubular shell and a seamless plastic liner,the liner having at one end a lip which extends over one edge of thetubular shell and at its opposite end being bonded to a container lidwhich it retains snugly against the opposite end of the supportingshell.

This application is a division of application Ser. No. 464,711, filedJune 17, 1965, now United States Patent 3,338,020.

The present invention relates to reinforced plastic lined containers.

Foil-fiber cans have received wide acceptance in many areas, andparticularly the oil industry which requires a light weight, disposableand comparatively inexpensive container for oil consumer products. Thesecans generally have metal lids attached to the ends of a tubular bodywhich consists of spirally wound inner and outer laminations of aluminumfoil and kraft paper and a central layer of kraft board. Regardless ofthe care employed during manufacture, leakage often occurs along thespiral seams of foil-fiber cans, especially after such cans haveundergone some jolting as might normally be expected during transit.While such cans are generally less expensive than all metal cans thefoil-fiber cans do employ costly materials, such as aluminum lids, andmust undergo a relatively large number of manipulative steps duringfabrication and filling. Accordingly, a primary object of this inventionis to provide an improved and more satisfactory plastic-lined container.

Another object is the provision of an improved container having a closefitting, continuous or unbroken and seamless plastic liner which isretained in position without the use of adhesives.

Still another object is the provision of a container having a generallyrigid tubular body which imparts strength to the container and aseamless plastic liner which extends along the inside wall of thetubular body and across one end thereof where it is attached to acontainer lid.

A further object is the provision of an improved reinforcedplastic-lined container which is strong but light in weight, simple inconstruction, easily disposed of after use and is made of inexpensivematerials.

Still further objects will appear from the following description.

The novelty of the container of the present invention resides in themanner by which a seamless and continuous or unbroken plastic linercooperates with a generally rigid supporting tubular shell and an endlid so as to be mechanically locked in a taut and substantially fixedposition. More particularly, the lid is disposed across and bearsagainst one end of the shell without being directly attached or adheredthereto. This lid, however, is bonded to the plastic liner which extendsalong the inside walls of the shell and across said one end.

At its open end the liner includes an integral and continuous lip whichprojects outwardly over and against the adjacent edge of the shell. Theliner lip and the end lid to which the liner is bonded thus cooperatetogether to Patented May 14, 1968 "ice lock the plastic liner againstany substantial longitudinal movement relative to the shell, but are notadhered thereto. Moreover, the plastic liner serves to retain thecontainer end lid in position against the shell, while the liner lipfacilitates a good seal between the liner and a subsequently applied toplid or cover and permits such top lid to be bonded in place.

In making the container of the present invention, a lid is positionedadjacent to but slightly spaced from one end of a tubular supportingshell and a sheet of thermoplastic material is disposed across andclamped against the opposite end of such shell. The thermoplasticmaterial is softened by heat and is vacuum formed, with a plug assist,against the walls of the shell and the end lid as a seamless andcontinuous or unbroken liner. During this operation the end lid is alsoheated to thermally bond the same to the portion of the plastic linerwith which it is engaged. The formed plastic liner and lid are thencooled. The plastic liner is not adhered to the shell and will normallyundergo slight shrinkage upon cooling which is generally sufficient todraw the attached lid snugly up against the adjacent edge of the shell.As a result, the plastic liner is free of any crimps or folds and issnugly locked against movement relative to the supporting shell.

Of particular interest in making the container of the present inventionis that the applied vaccum removes air from within the shell through thesmall space provided between shell and lid and, in addition draws theheated plastic liner toward this space wi;hout disturbing the unbrokencontinuity of the liner. Thus, in the finished container the plasticliner is supported along substantially all areas thereof.

If desired, the lined container of the present invention may be filledand covered before being removed from the forming apparatus. In thisinstance the clamp holding the thermoplastic material against the edgeof the shell is heated to enable the lip of the plastic liner to bond toan applied heated top lid.

As heretofore mentioned, the tubular supporting shell is of generallyrigid construction and may be formed of plastic, metal or laminatedlayers of fibrous materials.

,The container liner may be formed of any suitable thermoplasticmaterial which can be heated to its forming temperature without causingdamage to the shell or container lids. Polyethylene and polypropylenefilms, for example, are satisfactory. From the standpoint of simplicityand ease of manufacture, the thermoplastic material may be provided inthe form of precut or preformed disks which can be properly clamped tothe edge of the shell yet necessitate no subsequent trimming.

The container lids may be also formed from a variety of materials, suchas paper or metal and preferably of thermoplastic materials. The linerand lids need not be be of the same plastic material, although such aselection would simplify operating procedures and conditions. The lidsmust be sufficiently large so as to bear against the ends of thesupporting shell and are preferably of cupshape so as to fit over theends of such shells. If desired, the lids may be shaped with a centralcrown which extends into and reinforces the end of the shell.

For the sake of simplicity, the method employed in making the containerof the present invention is hereafter described using a tubular shellformed of laminated fibrous materials and a seamless and continuous orunbroken liner and end lids formed of polypropylene.

In the drawing, FIGURE 1 is a vertical section through a vacuum formingapparatus illustrating the positions of various parts which are employedin making the container of the present invention;

FIGURE 2 is a fragmentary view of a portion of the apparatus shown inFIGURE 1 and showing the positions of the various container parts duringa vacuum forming stage of the method employed in making the container ofthe present invention;

FIGURE 3 is a view similar to FIGURE 2 showing the various containerparts at the completion of the vacuum forming stage; and

FIGURE 4 is also a fragmentary view of a portion of the apparatus shownin FIGURE 1 illustrating the application of a container top lid.

With reference to the drawing, the method employed in making thecontainer of the present invention is practiced using a vacuum formingapparatus 11 which includes a conventional split tube clamp 13, amandrel 15 and a top clamp 17. Both the mandrel 15 and top clamp 17 areheated by suitable means, not shown. A tubular shell 19 formed oflaminated layers of fibrous material is fixed within the clamp 13 with asmall space 21 being provided between the bottom edge 23 of the shell 19and a lid 25 carried by the mandrel 15. A preformed disk 27 is thenfirmly gripped between the top edge 29 of the shell 19 and the clamp 17.The lid 25 and disk 27 are preferably formed of the same thermoplasticmaterial, which for the sake of description, may be polypropylene.

Before the actual forming operation is started the lid 25 and disk 27are heated to about 300 E, which is the forming temperature forpolypropylene, by heating the mandrel 13 and clamp 17 and, if necessary,by radiant heaters. Air is evacuated from within the shell 19 throughthe space 21 and an opening 31 on the split clamp 13.

As shown in FIGURE 1, a seal 33 is provided between the clamp 13 andshell 19 to confine the area which is to be evacuated.

concomitantly with or perhaps in advance of the vacuum application, aconventional heated plug 35 is engaged with the exposed surface of theheated disk 27 and assist in stretching the same into the form of aseamless and continuous or unbroken liner, as shown at 37 in FIGURE 1.As the evacuation of the shell 19 is being completed, as shown in FIGURE2, the pressure of the atmosphere on the exposed side of the liner urgesthe same well into the existing corner between the shell and lid 25. Ingeneral, the liner will be of gradually reduced thickness in the areaadjacent to the top clamp 17, and will conform with the inside wall ofthe shell 19 with which it engages. When engaged with the heated lid 25,however, the liner will not only conform with the surface thereof butwill bond thereto and provide an integral and relatively thick containerbottom wall.

The mandrel 15 and top clamp 17 are now cooled to set the liner 37 inits expanded shape. The liner 37 will under go a slight amount ofshrinkage during cooling and will thereby draw the lid 25 snugly upagainst the bottom edge 23 of the shell 19. At its opened end, the liner37 includes an outwardly projecting, continuous lip 39 which bearsagainst the top edge 29 of the shell 19. It will be apparent that in thefinished container the snug engagement of the lid 25 and liner lip 39with the opposite edges of the shell 19 prevent movement of the linerlongitudinally of the shell, and as a practical matter will prevent anyliner movement. The liner 37 presents a smooth seamless and continuousor unbroken surface which is free of crimps or folds and, as shown inFIG- URE 3, is supported along all areas and particularly along thecorners thereof.

The lined container may now be removed from the forming apparatus oralternatively may be filled and sealed while it remains in place. Inthis latter instance, the top clamp 17 is maintained hot so that theliner lip 39 is at its forming temperature when a top lid 41 issubsequently applied. The top lid 41 is preferably formed ofpolypropylene and is also heated by suitable means, not shown, to securea good bond between the liner 37 and lid 41.

It is to be understood that changes and variations may be made withoutdeparting from the spirit and scope of the present invention.

I claim:

1. A plastic lined container including a generally rigid tubular shellwhich is open at both ends thereof, a lid extending across and incontact with one end of said shell and a seamless liner formed ofthermoplastic material connected to said lid and extending snugly alongthe inside wall of said shell, said liner being free of said shell andat its open end extending over the edge of the shell which is oppositeto said one end thereof whereby the lid is retained in position againstsaid one end of the shell solely by said liner and the liner itself islocked against movement longitudinally of said shell.

2. A container as defined in claim 1 wherein said seamless liner isengaged with substantially all inside surfaces of said container and isin a generally taut condition within said shell and wherein the portionthereof extending over the edge of said shell is in the form of a lip.

3. A container as defined in claim 2 further including a lid thermallybonded to said liner lip.

4. A container as defined in claim 2 wherein said shell is formed offibrous material and said lid is formed of thermoplastic material.

References Cited UNITED STATES PATENTS 1,491,860 4/ 1924 Holden.

3,322,318 5/1967 Felton 229-55 X 3,306,488 2/ 1967 Lemelson 220-63FOREIGN PATENTS 1,183,528 1/1959 France.

DONALD F. NORTON, Primary Examiner.

JOSEPH R. LECLAIR, Examiner.

